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106-499: Literally, the name Ceará means "sings the jandaia ". According to José de Alencar , one of the most important writers of Brazil and an authority in Tupi Guaraní, Ceará means turquoise or green waters. The state is best known for its extensive coastline, with 600 kilometers (370 mi) of sand. There are also mountains and valleys producing tropical fruits . To the south, on the border of Paraíba , Pernambuco and Piauí ,

212-729: A tsunami . Earthquakes can trigger landslides . Earthquakes' occurrence is influenced by tectonic movements along faults, including normal, reverse (thrust), and strike-slip faults, with energy release and rupture dynamics governed by the elastic-rebound theory . Efforts to manage earthquake risks involve prediction, forecasting, and preparedness, including seismic retrofitting and earthquake engineering to design structures that withstand shaking. The cultural impact of earthquakes spans myths, religious beliefs, and modern media, reflecting their profound influence on human societies. Similar seismic phenomena, known as marsquakes and moonquakes , have been observed on other celestial bodies, indicating

318-571: A depth of less than 70 km (43 mi) are classified as "shallow-focus" earthquakes, while those with a focal depth between 70 and 300 km (43 and 186 mi) are commonly termed "mid-focus" or "intermediate-depth" earthquakes. In subduction zones, where older and colder oceanic crust descends beneath another tectonic plate, deep-focus earthquakes may occur at much greater depths (ranging from 300 to 700 km (190 to 430 mi)). These seismically active areas of subduction are known as Wadati–Benioff zones . Deep-focus earthquakes occur at

424-488: A depth where the subducted lithosphere should no longer be brittle, due to the high temperature and pressure. A possible mechanism for the generation of deep-focus earthquakes is faulting caused by olivine undergoing a phase transition into a spinel structure. Earthquakes often occur in volcanic regions and are caused there, both by tectonic faults and the movement of magma in volcanoes . Such earthquakes can serve as an early warning of volcanic eruptions, as during

530-475: A few exceptions to this: Supershear earthquake ruptures are known to have propagated at speeds greater than the S wave velocity. These have so far all been observed during large strike-slip events. The unusually wide zone of damage caused by the 2001 Kunlun earthquake has been attributed to the effects of the sonic boom developed in such earthquakes. Slow earthquake ruptures travel at unusually low velocities. A particularly dangerous form of slow earthquake

636-536: A mission to spy in the area of Ibiapaba. In October, that year Francisco Pinto was killed by the Indians and Pereira Filgueira returned with more information about the area and the French and Indian alliance. In 1612, the French were successfully expelled from Ceará and Maranhão by a military expedition under the command of Portuguese Martim Soares Moreno . In the same year he constructed the fortress of São Sebastião on

742-612: A particular location in the Earth is the average rate of seismic energy release per unit volume. One of the most devastating earthquakes in recorded history was the 1556 Shaanxi earthquake , which occurred on 23 January 1556 in Shaanxi , China. More than 830,000 people died. Most houses in the area were yaodongs —dwellings carved out of loess hillsides—and many victims were killed when these structures collapsed. The 1976 Tangshan earthquake , which killed between 240,000 and 655,000 people,

848-402: A particular time. The seismicity at a particular location in the Earth is the average rate of seismic energy release per unit volume. In its most general sense, the word earthquake is used to describe any seismic event that generates seismic waves. Earthquakes can occur naturally or be induced by human activities, such as mining , fracking , and nuclear tests . The initial point of rupture

954-529: A range is called a chapada or taboleira , and its width in places is from 32 to 56 miles (51 to 90 km). The boundary line with Piauí follows one of these ranges, the Serra de Ibiapaba , which unites with another range on the southern boundary of the state, known as the Serra do Araripe . Another range, or escarpment, crosses the state from east to west, but is broken into two principal divisions, each having several local names. These ranges are not continuous,

1060-765: A single rupture) are approximately 1,000 km (620 mi). Examples are the earthquakes in Alaska (1957) , Chile (1960) , and Sumatra (2004) , all in subduction zones. The longest earthquake ruptures on strike-slip faults, like the San Andreas Fault ( 1857 , 1906 ), the North Anatolian Fault in Turkey ( 1939 ), and the Denali Fault in Alaska ( 2002 ), are about half to one third as long as

1166-461: A sizable aviary to thrive. The genus Aratinga was introduced in 1824 by the German naturalist Johann Baptist von Spix . The type species was subsequently designated as the sun parakeet . The genus name is from the extinct Tupi language of Brasil. Ará tinga means "bright bird" or "bright parrot". The taxonomy of this genus has recently been resolved by splitting it in four genera, as

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1272-525: A width of 12 to 18 miles (19 to 29 km), is nearly bare of vegetation, although the coast has many enclaves of restingas (coastal forests) and mangroves . The soil is, in general, thin and porous and does not retain moisture; consequently, the long dry season turns the country into a barren desert, relieved only by vegetation along the riverways and mountain ranges, and by the hardy, widely distributed carnauba palm ( Copernicia cerifera ), which in places forms groves of considerable extent. Some areas in

1378-430: Is a genus of South American conures . Most are predominantly green, although a few are predominantly yellow or orange. They are social and commonly seen in groups in the wild. In Brazil , the popular name of several species usually is jandaia , sometimes written as jandaya in the scientific form. Many species from this genus are popular pets, although being larger than the members of the genus Pyrrhura , they need

1484-456: Is a succession of great terraces, facing north and northeast, formed by the denudation of the ancient sandstone plateau which once covered this part of the continent; the terraces are seamed by watercourses, and their valleys are broken by hills and ranges of highlands. The latter are the remains of the ancient plateau, capped with horizontal strata of sandstone, with a uniform altitude of 2,000 to 2,400 feet (610 to 730 m). The flat top of such

1590-525: Is a theory that earthquakes can recur in a regular pattern. Earthquake clustering has been observed, for example, in Parkfield, California where a long-term research study is being conducted around the Parkfield earthquake cluster. An aftershock is an earthquake that occurs after a previous earthquake, the mainshock. Rapid changes of stress between rocks, and the stress from the original earthquake are

1696-410: Is called the hypocenter or focus, while the ground level directly above it is the epicenter . Earthquakes are primarily caused by geological faults , but also by volcanic activity , landslides, and other seismic events. The frequency, type, and size of earthquakes in an area define its seismic activity, reflecting the average rate of seismic energy release. Significant historical earthquakes include

1802-526: Is carried out almost exclusively in the Northeast. The area occupied by cashew trees in Brazil in 2017 was estimated at 505,500 ha; of this total, 99.5% is located in the Northeast. The main producers in this region are Ceará (61.6% of the national area), Rio Grande do Norte and Piauí. However, Brazil, which in 2011 was the fifth largest world producer of cashew nuts, in 2016, fell to 14th position, with 1.5% of

1908-524: Is converted into heat generated by friction. Therefore, earthquakes lower the Earth's available elastic potential energy and raise its temperature, though these changes are negligible compared to the conductive and convective flow of heat out from the Earth's deep interior. There are three main types of fault, all of which may cause an interplate earthquake : normal, reverse (thrust), and strike-slip. Normal and reverse faulting are examples of dip-slip, where

2014-400: Is divided into 754 Flinn–Engdahl regions (F-E regions), which are based on political and geographical boundaries as well as seismic activity. More active zones are divided into smaller F-E regions whereas less active zones belong to larger F-E regions. Standard reporting of earthquakes includes its magnitude , date and time of occurrence, geographic coordinates of its epicenter , depth of

2120-577: Is one of only three Brazilian states which together produce the world's entire supply of carnauba wax. Share of the Brazilian economy: 2,16% (2021). According to the data from IPECE and IBGE , the GDP growth of the State of Ceará in 2021 was of 4.76%, while Brazil's overall GDP grew 4,76% as well in the same year. Traditionally an agriculture -based state, Ceará began an industrialisation program under

2226-545: Is probably a statistical fluctuation rather than a systematic trend. More detailed statistics on the size and frequency of earthquakes is available from the United States Geological Survey. A recent increase in the number of major earthquakes has been noted, which could be explained by a cyclical pattern of periods of intense tectonic activity, interspersed with longer periods of low intensity. However, accurate recordings of earthquakes only began in

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2332-423: Is proportional to the area of the fault that ruptures and the stress drop. Therefore, the longer the length and the wider the width of the faulted area, the larger the resulting magnitude. The most important parameter controlling the maximum earthquake magnitude on a fault, however, is not the maximum available length, but the available width because the latter varies by a factor of 20. Along converging plate margins,

2438-410: Is the tsunami earthquake , observed where the relatively low felt intensities, caused by the slow propagation speed of some great earthquakes, fail to alert the population of the neighboring coast, as in the 1896 Sanriku earthquake . During an earthquake, high temperatures can develop at the fault plane, increasing pore pressure and consequently vaporization of the groundwater already contained within

2544-621: Is the National Forest of Araripe . Ceará has an area of 148,016 square kilometres (57,149 sq mi). It is bounded on the north by the Atlantic Ocean , on the east by the states of Rio Grande do Norte and Paraíba , on the south by Pernambuco state, and on the west by Piauí . Ceará lies partly upon the northeast slope of the Brazilian Highlands , and partly upon the sandy coastal plain. Its surface

2650-825: Is very important in the culture of Ceará, being an extremely important factor in the construction of the identity of the people. Catholicism is the hegemony religion in Ceará and is the Christian confession that left most marks in Ceara's culture. It was the only one recognized by the government until 1883, when the Presbyterian Church of Fortaleza was founded in the state capital. Roman Catholicism in Ceará presents several influences of indigenous beliefs. A large portion of traditional Christian manifestations in Ceará are strongly influenced by religious syncretism. Throughout

2756-509: The 1556 Shaanxi earthquake in China, with over 830,000 fatalities, and the 1960 Valdivia earthquake in Chile, the largest ever recorded at 9.5 magnitude. Earthquakes result in various effects, such as ground shaking and soil liquefaction , leading to significant damage and loss of life. When the epicenter of a large earthquake is located offshore, the seabed may be displaced sufficiently to cause

2862-400: The 1980 eruption of Mount St. Helens . Earthquake swarms can serve as markers for the location of the flowing magma throughout the volcanoes. These swarms can be recorded by seismometers and tiltmeters (a device that measures ground slope) and used as sensors to predict imminent or upcoming eruptions. A tectonic earthquake begins as an area of initial slip on the fault surface that forms

2968-587: The 2004 Indian Ocean earthquake is simultaneously one of the deadliest earthquakes in history. Earthquakes that caused the greatest loss of life, while powerful, were deadly because of their proximity to either heavily populated areas or the ocean, where earthquakes often create tsunamis that can devastate communities thousands of kilometers away. Regions most at risk for great loss of life include those where earthquakes are relatively rare but powerful, and poor regions with lax, unenforced, or nonexistent seismic building codes. Tectonic earthquakes occur anywhere on

3074-594: The Aptian sediments of Crato Formation. The animal was named Cratoavis cearensis , after formation and state’s naming. The territory of Ceará was originally inhabited by different Indian peoples, such as the Tabajara, Potyguara, Anacés, Kariri, Inhamum, Jucá, Kanindé, Tremembé, Paicaú and others, who had commercial relations with various European people, including the French, before the Portuguese decided to include

3180-462: The Guadeloupe parakeet ( Aratinga labati ). No specimens or remains of the extinct parrots are known. Their taxonomy may never be fully elucidated, so their postulated status as a separate species is hypothetical, and it is regarded as a hypothetical extinct species . Earthquake An earthquake  – also called a quake , tremor , or temblor  – is

3286-499: The Himalayan Mountains . With the rapid growth of mega-cities such as Mexico City, Tokyo, and Tehran in areas of high seismic risk , some seismologists are warning that a single earthquake may claim the lives of up to three million people. While most earthquakes are caused by the movement of the Earth's tectonic plates , human activity can also produce earthquakes. Activities both above ground and below may change

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3392-716: The Orós Dam , comparable in size to the Aswan Dam has supplied Ceará with much of its water, and in 1995 construction began on the enormous Castanhão Dam , completed in 2003, which is able to hold 6.5 km of water. Ceará is governed by the Governor of Ceará , currently Elmano de Freitas since 2023, and the Legislative Assembly of Ceará . According to the IBGE of 2008, there were 8,472,000 people residing in

3498-426: The brittle-ductile transition zone and upwards by the ground surface. The mechanics of this process are poorly understood because it is difficult either to recreate such rapid movements in a laboratory or to record seismic waves close to a nucleation zone due to strong ground motion. In most cases, the rupture speed approaches, but does not exceed, the shear wave (S wave) velocity of the surrounding rock. There are

3604-413: The least principal stress. Strike-slip faulting is intermediate between the other two types described above. This difference in stress regime in the three faulting environments can contribute to differences in stress drop during faulting, which contributes to differences in the radiated energy, regardless of fault dimensions. For every unit increase in magnitude, there is a roughly thirty-fold increase in

3710-498: The military regime (1964–1985), and the industrial sector continues to expand annually. In 1999, industry accounted for 39.3% of the state's GDP . Tourism also plays a large role in Ceará's economy, with the state's many waterfalls , beaches and rainforests . On average, Fortaleza alone receives half a million tourists annually. In agriculture, the state stands out in the production of cashew nuts , coconut , papaya , melon and beans . The production of cashew in Brazil

3816-553: The 20th century and has been inferred for older anomalous clusters of large earthquakes in the Middle East. It is estimated that around 500,000 earthquakes occur each year, detectable with current instrumentation. About 100,000 of these can be felt. Minor earthquakes occur very frequently around the world in places like California and Alaska in the U.S., as well as in El Salvador, Mexico, Guatemala, Chile, Peru, Indonesia,

3922-630: The 20th century, several churches were installed in the State and at the end of that century there was a considerable increase in people from other religions. However, Ceará is still the third Brazilian state with the highest proportion of Roman Catholics, 78.8% of the population, according to data from 2010 census. Evangelicals are 14.6%, Spiritists, 0.6%, members of other religions, 2.0%, and those without religion, 4.0%. Vehicles : 1,084,991 (March/2007); Mobile phones : 3.5 million (April/2007); Telephones : 908 thousand (April/2007); Cities : 184 (2007). There are more than 53 higher education institutions in

4028-433: The 21st century. Seismic waves travel through the Earth's interior and can be recorded by seismometers at great distances. The surface-wave magnitude was developed in the 1950s as a means to measure remote earthquakes and to improve the accuracy for larger events. The moment magnitude scale not only measures the amplitude of the shock but also takes into account the seismic moment (total rupture area, average slip of

4134-399: The Earth's core was located in 1913 by Beno Gutenberg . S waves and later arriving surface waves do most of the damage compared to P waves. P waves squeeze and expand the material in the same direction they are traveling, whereas S waves shake the ground up and down and back and forth. Earthquakes are not only categorized by their magnitude but also by the place where they occur. The world

4240-484: The Earth. Also, the depth of the hypocenter can be computed roughly. P wave speed S waves speed As a consequence, the first waves of a distant earthquake arrive at an observatory via the Earth's mantle. On average, the kilometer distance to the earthquake is the number of seconds between the P- and S wave times 8. Slight deviations are caused by inhomogeneities of subsurface structure. By such analysis of seismograms,

4346-540: The Indians attacked the Dutch Governor of Ceará, Gideon Morris , the Dutch soldiers were killed, and São Sebastião was destroyed. There were no Europeans in the region between 1644 and 1649, but in 1649, before negotiations with the different Indian tribes, Matias Beck arrived in Ceará to explore silver mines of Maranguape . Good-quality silver was not found however. In this period the Dutch built another fort, by

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4452-545: The Philippines and India, the world's largest producers, who even export coconut water to Brazil. In addition to climatic problems, the low productivity of coconut palms in the Northeast Region is the result of factors related to the variety of coconut harvested and the technological level used in coastal regions. In these areas, the semi-extractive cultivation system still prevails, with low fertility and without

4558-513: The Philippines, Iran, Pakistan, the Azores in Portugal, Turkey, New Zealand, Greece, Italy, India, Nepal, and Japan. Larger earthquakes occur less frequently, the relationship being exponential ; for example, roughly ten times as many earthquakes larger than magnitude 4 occur than earthquakes larger than magnitude 5. In the (low seismicity) United Kingdom, for example, it has been calculated that

4664-495: The Portuguese crown, ending conflict in the region. Ceará became a dependency of Pernambuco in 1680; this relationship lasted until 1799, when the Captaincy of Ceará was made independent. The fight for Brazilian independence in 1822 was fierce in Ceará, with the area being a rebel stronghold that incurred vicious retribution from loyalists. The captaincy became a province in 1822 under Dom Pedro I. A revolution followed in 1824,

4770-463: The adoption of cultural management practices. The three states that have the largest production, Bahia, Sergipe and Ceará, present a yield three times lower than that of Pernambuco, which is in 5th place in the national production. This is because most of the coconut trees in these three states are located in coastal areas and cultivated in semi-extractivist systems. In 2018, the South Region was

4876-488: The area in Brazil. The first Portuguese plan for settling in Ceará dated from 1534, but the first attempts to settle the territory failed, and the earliest Portuguese settlement was made near the mouth of the Ceará River in 1603, by Pero Coelho de Sousa. He established the fort of São Tiago, but one year later he and his family abandoned Ceará because of a period of drought, a natural phenomenon that periodically afflicts

4982-463: The average recurrences are: an earthquake of 3.7–4.6 every year, an earthquake of 4.7–5.5 every 10 years, and an earthquake of 5.6 or larger every 100 years. This is an example of the Gutenberg–Richter law . The number of seismic stations has increased from about 350 in 1931 to many thousands today. As a result, many more earthquakes are reported than in the past, but this is because of

5088-577: The banks of river Pajeú, and named it Fort Schoonenborch after one of their commanders. In 1654, the Dutch were expelled from Brazil; the Portuguese took Schoonenborch, changed its name to Fortaleza de Nossa Senhora de Assunção (The Fortress of Our Lady of the Assumption), and the different Indian tribes that had made alliance with the Dutch had to flee from Portuguese persecution. In 1661, the Netherlands formally ceded their Brazilian territories to

5194-502: The breaking down of the ancient plateau having been irregular and uneven. The rivers of the state are small and, with one or two exceptions, become completely dry in the dry season. The largest is the Jaguaribe , which flows entirely across the state in a northeast direction. Ceará has a varied environment, with mangroves , caatinga , jungle , scrubland and tropical forest . The higher ranges intercept considerable moisture from

5300-404: The brittle crust. Thus, earthquakes with magnitudes much larger than 8 are not possible. In addition, there exists a hierarchy of stress levels in the three fault types. Thrust faults are generated by the highest, strike-slip by intermediate, and normal faults by the lowest stress levels. This can easily be understood by considering the direction of the greatest principal stress, the direction of

5406-483: The capital Fortaleza ): Sunset Coast ( Costa do Sol poente ) and Sunrise Coast ( Costa do Sol nascente ). Ceará lies in one of the few regions of the country that experiences earthquakes . In 1980 an earthquake measuring 5.8 on the Richter scale struck near Quixeramobim in the center of the state, rattling the city of Fortaleza but causing no injuries. The climate of Ceará is hot almost all year. The temperature in

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5512-512: The cause of other earthquakes in the past century. A Columbia University paper suggested that the 8.0 magnitude 2008 Sichuan earthquake was induced by loading from the Zipingpu Dam , though the link has not been conclusively proved. The instrumental scales used to describe the size of an earthquake began with the Richter scale in the 1930s. It is a relatively simple measurement of an event's amplitude, and its use has become minimal in

5618-594: The commerce increasing by a large amount, and with gas lighting becoming almost ubiquitous. The state of Ceará became a bishopric of the Roman Catholic Church in 1853, the bishop residing at Fortaleza. Two railway lines running inland from the coast (the Baturité line from Fortaleza to Senador Pompeu, 179 miles (288 km), and the Sobral line from the port of Camocim to Ipu, 134 miles), were built by

5724-529: The dip angle of the rupture plane is very shallow, typically about 10 degrees. Thus, the width of the plane within the top brittle crust of the Earth can reach 50–100 km (31–62 mi) (such as in Japan, 2011 , or in Alaska, 1964 ), making the most powerful earthquakes possible. The majority of tectonic earthquakes originate in the Ring of Fire at depths not exceeding tens of kilometers. Earthquakes occurring at

5830-678: The displacement along the fault is in the direction of dip and where movement on them involves a vertical component. Many earthquakes are caused by movement on faults that have components of both dip-slip and strike-slip; this is known as oblique slip. The topmost, brittle part of the Earth's crust, and the cool slabs of the tectonic plates that are descending into the hot mantle, are the only parts of our planet that can store elastic energy and release it in fault ruptures. Rocks hotter than about 300 °C (572 °F) flow in response to stress; they do not rupture in earthquakes. The maximum observed lengths of ruptures and mapped faults (which may break in

5936-439: The distance from the earthquake and the underlying rock or soil makeup. The first scale for measuring earthquake magnitudes was developed by Charles Francis Richter in 1935. Subsequent scales ( seismic magnitude scales ) have retained a key feature, where each unit represents a ten-fold difference in the amplitude of the ground shaking and a 32-fold difference in energy. Subsequent scales are also adjusted to have approximately

6042-554: The early 1900s, so it is too early to categorically state that this is the case. Most of the world's earthquakes (90%, and 81% of the largest) take place in the 40,000-kilometre-long (25,000 mi), horseshoe-shaped zone called the circum-Pacific seismic belt, known as the Pacific Ring of Fire , which for the most part bounds the Pacific plate . Massive earthquakes tend to occur along other plate boundaries too, such as along

6148-403: The earth where there is sufficient stored elastic strain energy to drive fracture propagation along a fault plane . The sides of a fault move past each other smoothly and aseismically only if there are no irregularities or asperities along the fault surface that increases the frictional resistance. Most fault surfaces do have such asperities, which leads to a form of stick-slip behavior . Once

6254-426: The earthquakes strike a fault in clusters, each triggered by the shaking or stress redistribution of the previous earthquakes. Similar to aftershocks but on adjacent segments of fault, these storms occur over the course of years, with some of the later earthquakes as damaging as the early ones. Such a pattern was observed in the sequence of about a dozen earthquakes that struck the North Anatolian Fault in Turkey in

6360-504: The energy released. For instance, an earthquake of magnitude 6.0 releases approximately 32 times more energy than a 5.0 magnitude earthquake and a 7.0 magnitude earthquake releases 1,000 times more energy than a 5.0 magnitude earthquake. An 8.6-magnitude earthquake releases the same amount of energy as 10,000 atomic bombs of the size used in World War II . This is so because the energy released in an earthquake, and thus its magnitude,

6466-465: The entire region. The most destructive droughts recorded in the 18th and 19th centuries were those of 1711, 1723, 1777–1778, 1790, 1825, 1844–1845, and 1877–1880 , the last-mentioned (known by local people as a Grande Seca , "the Great Drought") destroying nearly all the livestock in the state, and causing the death through starvation and pestilence of nearly half a million people, or over half

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6572-458: The fact that no single earthquake in the sequence is the main shock, so none has a notably higher magnitude than another. An example of an earthquake swarm is the 2004 activity at Yellowstone National Park . In August 2012, a swarm of earthquakes shook Southern California 's Imperial Valley , showing the most recorded activity in the area since the 1970s. Sometimes a series of earthquakes occur in what has been called an earthquake storm , where

6678-462: The fault has locked, continued relative motion between the plates leads to increasing stress and, therefore, stored strain energy in the volume around the fault surface. This continues until the stress has risen sufficiently to break through the asperity, suddenly allowing sliding over the locked portion of the fault, releasing the stored energy . This energy is released as a combination of radiated elastic strain seismic waves , frictional heating of

6784-411: The fault plane that holds it in place, and fluids can exert a lubricating effect. As thermal overpressurization may provide positive feedback between slip and strength fall at the fault plane, a common opinion is that it may enhance the faulting process instability. After the mainshock, the pressure gradient between the fault plane and the neighboring rock causes a fluid flow that increases pore pressure in

6890-418: The fault surface, and cracking of the rock, thus causing an earthquake. This process of gradual build-up of strain and stress punctuated by occasional sudden earthquake failure is referred to as the elastic-rebound theory . It is estimated that only 10 percent or less of an earthquake's total energy is radiated as seismic energy. Most of the earthquake's energy is used to power the earthquake fracture growth or

6996-541: The fault, and rigidity of the rock). The Japan Meteorological Agency seismic intensity scale , the Medvedev–Sponheuer–Karnik scale , and the Mercalli intensity scale are based on the observed effects and are related to the intensity of shaking. The shaking of the earth is a common phenomenon that has been experienced by humans from the earliest of times. Before the development of strong-motion accelerometers,

7102-417: The focus. Once the rupture has been initiated, it begins to propagate away from the focus, spreading out along the fault surface. Lateral propagation will continue until either the rupture reaches a barrier, such as the end of a fault segment, or a region on the fault where there is insufficient stress to allow continued rupture. For larger earthquakes, the depth extent of rupture will be constrained downwards by

7208-406: The force that "pushes" the rock mass during the faulting. In the case of normal faults, the rock mass is pushed down in a vertical direction, thus the pushing force ( greatest principal stress) equals the weight of the rock mass itself. In the case of thrusting, the rock mass "escapes" in the direction of the least principal stress, namely upward, lifting the rock mass, and thus, the overburden equals

7314-548: The fort of São Sebastião lost its importance. At this time, what is today Brazil was hotly disputed by the Dutch and the Portuguese. The area was invaded twice by the Dutch, in 1637 and in 1649. In 1637, the Dutch and the Indians took the Fort of São Sebastião and dominated Ceará. The Dutch expanded their presence in Ceará and made alliances with different Indian tribes. In 1639, Georg Marcgrave made an expedition in Ceará, but in 1644

7420-534: The genus as previously defined was paraphyletic . The species of the Aratinga solstitialis complex were retained in this genus, while other former Aratinga species were moved to Eupsittula (brownish-throated species), Psittacara (pale-beaked species) and Thectocercus (blue-crowned parakeet). Furthermore, the closely related nanday parakeet ( A. nenday ) and the dusky-headed parakeet ( A. weddellii ) are placed in this genus. The nanday parakeet

7526-479: The giant cashew trees, which are the majority in the Region, are exploited in an almost extractive manner, with low use of technology. In 2017, the Northeast Region was the largest producer of coconut in the country, with 74.0% of national production. Bahia produced 351 million fruits, Sergipe, 234 million, and Ceará 187 million. However, the sector has been suffering strong competition and losing market to Indonesia,

7632-403: The higher ranges of Serra da Ibiapaba, Serra do Araripe and others are more appropriate for agriculture, as their soil and vegetation are less affected by the dry seasons. The beaches of the state are a major tourist attraction. Ceará has several famous beaches such as Canoa Quebrada , Jericoacoara , Morro Branco , Taíba and Flexeiras . The beaches are divided into two groups (in relation to

7738-435: The installed capacity for processing cashew nuts in the Northeast, however, the Region only managed to produce around a quarter of that quantity. Among the main world producers, Brazil has the lowest productivity. Several factors are pointed out as the cause of the low productivity and the fall in the Brazilian production of cashew nuts. One reason is that most orchards are in a phase of natural decline in production. In addition,

7844-410: The intensity of a seismic event was estimated based on the observed effects. Magnitude and intensity are not directly related and calculated using different methods. The magnitude of an earthquake is a single value that describes the size of the earthquake at its source. Intensity is the measure of shaking at different locations around the earthquake. Intensity values vary from place to place, depending on

7950-476: The lengths along subducting plate margins, and those along normal faults are even shorter. Normal faults occur mainly in areas where the crust is being extended such as a divergent boundary . Earthquakes associated with normal faults are generally less than magnitude 7. Maximum magnitudes along many normal faults are even more limited because many of them are located along spreading centers, as in Iceland, where

8056-402: The main causes of these aftershocks, along with the crust around the ruptured fault plane as it adjusts to the effects of the mainshock. An aftershock is in the same region as the main shock but always of a smaller magnitude, however, they can still be powerful enough to cause even more damage to buildings that were already previously damaged from the mainshock. If an aftershock is larger than

8162-472: The main producer of beans with 26.4% of the total, followed by the Midwest (25.4%), Southeast Region (25.1%), Northeast (20.6%) and North (2.5%). The largest producers in the Northeast were Ceará and Bahia. In cassava production, Brazil produced a total of 17.6 million tons in 2018. Maranhão was the 7th largest producer in the country, with 681 thousand tons. Ceará was 9th, with 622 thousand tons. In total,

8268-414: The mainshock, the aftershock is redesignated as the mainshock and the original main shock is redesignated as a foreshock . Aftershocks are formed as the crust around the displaced fault plane adjusts to the effects of the mainshock. Earthquake swarms are sequences of earthquakes striking in a specific area within a short period. They are different from earthquakes followed by a series of aftershocks by

8374-437: The national government after the drought of 1877–1878 to give work to the starving refugees, and were later operated under leases. Dams were also built for irrigation purposes. The population numbered 805,687 in 1890, and 849,127 in 1900. In 1900, approximately five-sixths of the population lived on estates, owned no property, paid no taxes, and derived few benefits from the social and political institutions about them. Education

8480-435: The northeast produced 3,5 million tons. Rio Grande do Norte is the largest producer of melon in the country. In 2017 it produced 354 thousand tons. The Northeast region accounted for 95.8% of the country's production in 2007. In addition to Rio Grande do Norte, which in 2005 produced 45.4% of the country's total, the other 3 largest in the country were Ceará, Bahia and Pernambuco. In the production of papaya , in 2018 Bahia

8586-607: The population. Because of the constant risk of droughts, many dams (called açudes ) have been built throughout Ceará, the largest of them the Açude Castanhão . Because of the dams, the Jaguaribe River no longer dries up completely. The state contains outcrops of the Early Cretaceous Crato and Santana formations. In 2015, the earliest South American enantiornithine bird was described from

8692-552: The president of the province was deposed fifteen days after his arrival, and a republic was proclaimed. Internal dissensions immediately broke out, the new president was assassinated, and after a brief reign of terror the province resumed its allegiance to the empire. Ceará became the first province of Brazil to abolish slavery, on March 25, 1884, more than four years before the 1888 national law of abolition, passed by Princess Isabel. The reign of Dom Pedro II (see Empire of Brazil ) saw great advances in infrastructure in Ceará, with

8798-443: The prevailing trade winds, and their flanks and valleys are covered with a tropical forest which is typical of the region, gathering species from tropical forests, caatinga and cerrado . The less elevated areas of the plateaus are either thinly wooded or open campo. Most of the region at the lower altitudes is characterized by scrubby forests called caatingas , which is an endemic Brazilian vegetation. The sandy, coastal plain, with

8904-523: The province, which the Portuguese settlers were ill-equipped to endure. Portugal wanted to form a military base in Ceará to support the Portuguese operations in the war against the French. The first attempt with Pero Coelho de Sousa , in 1603, was not successful, and the French continued operating from Maranhão and Ibiapaba , where they had established a base in 1590. The Indians and French formed political and military alliances. In 1607, two Jesuits, Francisco Pinto and Pereira Figueira, arrived in Ceará with

9010-530: The rock. In the coseismic phase, such an increase can significantly affect slip evolution and speed, in the post-seismic phase it can control the Aftershock sequence because, after the main event, pore pressure increase slowly propagates into the surrounding fracture network. From the point of view of the Mohr-Coulomb strength theory , an increase in fluid pressure reduces the normal stress acting on

9116-437: The rupture of geological faults but also by other events such as volcanic activity, landslides, mine blasts, fracking and nuclear tests . An earthquake's point of initial rupture is called its hypocenter or focus. The epicenter is the point at ground level directly above the hypocenter. The seismic activity of an area is the frequency, type, and size of earthquakes experienced over a particular time. The seismicity at

9222-522: The same numeric value within the limits of the scale. Although the mass media commonly reports earthquake magnitudes as "Richter magnitude" or "Richter scale", standard practice by most seismological authorities is to express an earthquake's strength on the moment magnitude scale, which is based on the actual energy released by an earthquake, the static seismic moment. Every earthquake produces different types of seismic waves, which travel through rock with different velocities: Propagation velocity of

9328-631: The same site as São Tiago, and one year later he left Ceará for Portugal. It was only in 1618 that Martim Soares Moreno returned to Ceará, and it is from this time that the Portuguese presence dates. This was restricted at first to the area of the Ceará River: Martim Soares Moreno made an alliance with the Indians of the Potiguara tribe. In 1631, he left Ceará to help the Portuguese against the Dutch in Pernambuco and

9434-464: The seismic waves through solid rock ranges from approx. 3 km/s (1.9 mi/s) up to 13 km/s (8.1 mi/s), depending on the density and elasticity of the medium. In the Earth's interior, the shock- or P waves travel much faster than the S waves (approx. relation 1.7:1). The differences in travel time from the epicenter to the observatory are a measure of the distance and can be used to image both sources of earthquakes and structures within

9540-449: The shaking of the Earth 's surface resulting from a sudden release of energy in the lithosphere that creates seismic waves . Earthquakes can range in intensity , from those so weak they cannot be felt, to those violent enough to propel objects and people into the air, damage critical infrastructure, and wreak destruction across entire cities. The seismic activity of an area is the frequency, type, and size of earthquakes experienced over

9646-399: The state of Ceará The service sector is the largest component of GDP at 73.28%, followed by the industrial sector at 20.49%. Agriculture represents 6.23% of GDP (2021). Ceará exports: cast iron, iron and steel (53,08%), shoes and similar artifacts (13,12%), fruits (7,66%), mineral fuels and derived products (3,81%), fish, crustaceans and other aquatic invertebrates (3,68%) (2023). It

9752-521: The state varies from 22 to 36 °C (72 to 97 °F). The coast is hot and humid, tempered by the cool trade winds; in the more elevated, semi-arid regions it is very hot and dry (often above 22 °C (72 °F), but seldom above 30 °C (86 °F)), although the nights are cool. In the higher ranges (Serra da Ibiapaba, Chapada do Araripe and several smaller highlands) the temperatures are cooler and vary from about 14 to 18 °C (57 to 64 °F). The record minimum temperature registered in Ceará

9858-475: The state. The population density was 55.2 inhabitants/km. Urbanization : 76.4% (2006); Population growth : 1.7% (1991–2000); Houses : 2,181,000 (2006). The last PNAD (National Research for Sample of Domiciles) census revealed the following numbers: 5,690,973 Brown ( Multiracial ) people (64.7%), 2,456,214 White people (27.9%), 595,694 Black people (6.8%), 39,982 Amerindian people (0.5%), 11,256 Asian people (0.1%). Religion in Ceará (2010) Religion

9964-422: The stresses and strains on the crust, including building reservoirs, extracting resources such as coal or oil, and injecting fluids underground for waste disposal or fracking . Most of these earthquakes have small magnitudes. The 5.7 magnitude 2011 Oklahoma earthquake is thought to have been caused by disposing wastewater from oil production into injection wells , and studies point to the state's oil industry as

10070-490: The surrounding fracture networks; such an increase may trigger new faulting processes by reactivating adjacent faults, giving rise to aftershocks. Analogously, artificial pore pressure increase, by fluid injection in Earth's crust, may induce seismicity . Tides may trigger some seismicity . Most earthquakes form part of a sequence, related to each other in terms of location and time. Most earthquake clusters consist of small tremors that cause little to no damage, but there

10176-443: The thickness of the brittle layer is only about six kilometres (3.7 mi). Reverse faults occur in areas where the crust is being shortened such as at a convergent boundary . Reverse faults, particularly those along convergent boundaries, are associated with the most powerful earthquakes (called megathrust earthquakes ) including almost all of those of magnitude 8 or more. Megathrust earthquakes are responsible for about 90% of

10282-461: The total seismic moment released worldwide. Strike-slip faults are steep structures where the two sides of the fault slip horizontally past each other; transform boundaries are a particular type of strike-slip fault. Strike-slip faults, particularly continental transforms , can produce major earthquakes up to about magnitude 8. Strike-slip faults tend to be oriented near vertically, resulting in an approximate width of 10 km (6.2 mi) within

10388-399: The total volume of nuts produced in the world. Vietnam, Nigeria, India and Côte d'Ivoire were the world's largest cashew nut producers in 2016, with 70.6% of global production. In recent years, there has been increased competition with some African countries, where government programs have driven the expansion of culture and processing capacity. It is estimated that at 295 thousand tons per year

10494-505: The universality of such events beyond Earth. An earthquake is the shaking of the surface of Earth resulting from a sudden release of energy in the lithosphere that creates seismic waves . Earthquakes may also be referred to as quakes , tremors , or temblors . The word tremor is also used for non-earthquake seismic rumbling . In its most general sense, an earthquake is any seismic event—whether natural or caused by humans—that generates seismic waves. Earthquakes are caused mostly by

10600-436: The vast improvement in instrumentation, rather than an increase in the number of earthquakes. The United States Geological Survey (USGS) estimates that, since 1900, there have been an average of 18 major earthquakes (magnitude 7.0–7.9) and one great earthquake (magnitude 8.0 or greater) per year, and that this average has been relatively stable. In recent years, the number of major earthquakes per year has decreased, though this

10706-667: Was 8 °C (46 °F), recorded in Jardim, a small city in Chapada do Araripe . The year is divided into a rainy and dry season, the rains beginning in January to March and lasting until June. The dry season, July to December, is sometimes broken by slight showers in September and October, but these are of slight importance. Sometimes the rains fail altogether, and then a drought ( seca ) ensues, causing famine and pestilence throughout

10812-570: Was important, and included manigoba or Ceará rubber, carnahuba wax and fibre, cashew wine and ipecacuanha. The principal agricultural products were cotton, coffee, sugar, manioc and tropical fruits. The production of cotton increased largely with the development of cotton manufacture in Brazil. The higher plateau was devoted almost exclusively to cattle raising, once the principal industry of the state, although recurring droughts created an obstacle to its profitable development. The state exported considerable amounts of cattle, hides and skins. Since 1960,

10918-469: Was previously placed in its own genus based on the differences in coloration and elongated upper mandible, but this was not supported by phylogenetic studies that showed a close relationship with the A. solstitialis species complex. . Jean-Baptiste Labat described a population of small parrots living on Guadeloupe , which has been postulated to be a separate species based on little evidence. They were called Conurus labati , and are now referred to as

11024-437: Was the 2nd largest producer state in Brazil, almost equaling with Espírito Santo. Ceará was in 3rd place and Rio Grande do Norte in 4th place. In the production of banana , in 2018 Ceará was the 8th largest national producer, with 408 thousand tons. Aratinga Aratinga solstitialis Aratinga maculata Aratinga jandaya Aratinga auricapilla Aratinga nenday Aratinga weddellii Aratinga

11130-641: Was the deadliest of the 20th century. The 1960 Chilean earthquake is the largest earthquake that has been measured on a seismograph, reaching 9.5 magnitude on 22 May 1960. Its epicenter was near Cañete, Chile. The energy released was approximately twice that of the next most powerful earthquake, the Good Friday earthquake (27 March 1964), which was centered in Prince William Sound , Alaska. The ten largest recorded earthquakes have all been megathrust earthquakes ; however, of these ten, only

11236-411: Was then confined almost exclusively to the upper classes, from which came some of the most prominent men in Brazilian politics and literature. In the early 20th century the sandy zone along the coast was nearly barren, but the more elevated region behind the coast with broken surfaces and sandy soil produced fruit and most tropical products when conditions were favourable. The natural vegetable production

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